Question: Simplify the following expression: $k = \dfrac{30qr}{30pr} - \dfrac{20pr}{30pr}$ You can assume $p,q,r \neq 0$.
Explanation: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{30qr - (20pr)}{30pr}$ $k = \dfrac{30qr - 20pr}{30pr}$ The numerator and denominator have a common factor of $10r$, so we can simplify $k = \dfrac{3q - 2p}{3p}$